Electrically controlled tool



Sept. 26, 1933. 5.7L. VIGNE ELECTRICALLY CONTROLLED TOOL Filed July 19,1932 2 Sheets-Sheet l Sept. 26, 1933. VIGNE I 1,928,082

ELECTRICALLY CONTROLLED TOOL Filed July 19, 1932 2 Sheets-Sheet 2 IPatented 26, 1933 4 UNITED; STATES" PATENT oFFICEg 3 Claims.

My invention has for its object an electrically controlled striker orhammering tool wherein the rotation of a shaft driven by an electricmotor is transformed into a reciprocating striking motion 5 parallel tothis shaft through the agency of a cam capable of a rotary and of arectilinear movement with reference to the shaft to which it isconnected through a coil spring wound round the shaft; this camcooperates with rollers which cause said cam when it rotates to riseperiodically against the action of the spring.

The objects of my invention are to provide inter-alia a tool which maybe mounted and dismounted in a simple manner, which is light andplications of which is greatly increased.

Thus the casing constituted of two parts and secured to the electricmotor extends in a direction parallel to the motor shaft and is arrangedin a manner such that the diflerent parts which it contains and guidesmay be readily accessible after an easy dismantling.

The connection between the spring on one hand and the rotary shaft andthe cam freely mounted on it on the other is provided simply by thecoils of the spring itself, which coils brought into close contacttowards both ends of the spring form a thread engaging screw threads ofopposed direction formed respectively on the shaft and on the cam.

The elastic return of the tool after striking and the holding of thetool in the casing are also ensured by a coil spring the upper coils ofwhich form a thread engaging a screw thread at the end of the toolcasing while its lower coils disposed in a common plane perpendicular tothe axis of the spring so as to reduce the diameter thereof, serve as abearing for a removable washer inserted in the tool handle.

In order to allow an easy handling of the tool by the workman who usesit, I provide in a peripheral groove of the tool casing, a collarprovided with a handle and carrying stops adapted to engage the casingwhereby it is possible to secure the handle ,in any desired angularposition with reference to the tool.

The starting of the tool is ensured as in all similar tools through theagency of a contact adapted to be closed by a knob controlled by theoperator. A stop system is provided which allows the operator to lockthe knob in its contact closing position whereby he may work withouthaving to keep the knob down.

Tools according to my invention are suitable for work in stone andmasonry, for instance for easily portable and the number of possible ap7 sculpture, scraping concrete surfaces, pricking up coatings, removingrust or paint, removin'g scale from boilers, cleaning ship's hulls,boring cement, brick, soft stone, pulling down buildings, vibratingreinforced concrete, or foundry molds, paring off, setting metals,stamping, riveting etc.

It allows the cutting of rubber tires, of thick sheets of lead, of clay,asphaltum, ice, etc.

I have described hereinbelow by way of example. and illustrated inaccompanying drawings a form of execution wherein: Y Fig. 1 is a sideview of the tool, partly in axial cross-section,

Fig. 2 is a detail side view of the striking system with the casingshown in cross-section,

Figs. 3 and 4 are cross-sections at an enlarged scale through lines ABand CD of Fig. 1 respectively.

The apparatus comprises a casing 1 constituted of two parts securedtogether at 1 and carrying in a suitable manner an ironclad electricmotor 2 carrying in its turn a handle 3 through which enters theelectric cable 4 fed from contained inside the upper part of the casing,

from the main shaft of the motor 2. The lower end of the shaft 5 engagesa recess bored in the cam 8. This cam carries slopes (Fig. 2)cooperating with rollers 9 mounted on spindles 11 screwed into thecasing wall. The vertical guiding of the cam along the shaft may howeverbe ensured in any other manner. A coil spring 12 fitted over the shaft 5connects this shaft with the cam. To this end the shaft 5 carries aninwardly threaded sleeve 13. This thread is engaged by the upper coilsof the spring 12 which are brought vertically into close relationship soas to form a kind of screw. 0n the other hand the cam 8 shows anoutwardly threaded boss 14 the new thread on which is engaged by thelower coils of the spring 12 which are also brought vertically intoclose relationship. Of course the direction of the threads is such thatfor the direction of rotation given by the motor 2 to the shaft 5, thesleeve 13 has a tendency to be screwed on to the spring. Obviously also,the cam may show an inner thread and the shaft an outer thread. Or againthe threads on the shaft and on the cam may be bothvouter threads orboth inner threads. I provide thus between the shaft 5 and the cam 8 ayielding connection allowing a very easy disconnection. The projectingpart 15 of the cam abuts directly against the upper partofthecarrierldofthetooll'l. Thiscarrier guided by the lower end of the casing 1. isprovided with a groove comprised between the two shoulders 18, 19 and inwhich is fitted the two part washer 21. The shoulder 18 and the washer21 are held inside a recess 22 provided at the end of the casing 1. Thisretaining action is ensured through a coil spring 23 theupper coils 25"(Fig. 3) interconnected through the screws I close the circuit 26. Thiscollar carries a handle 2''! inside which is axially arranged a spindle28 submitted to the action of a spring 29. The end of this spindle mayengage one of a series of recesses 31 provided at the periphery of thecasing 1. The spindle is acted upon through a knob 32. Obviously whenthe spindle 28 is urged backwards by the knob 32, it is .possible tomake the collar 25 rotate round the casing soas to secure it in one of aseries of positions corresponding to coincidence between the spindle 28and the different recesses 31. This allows the handle vto be set in theposition which is the most suitable for work.

The handle 3 carries a perforated plate 33 behind which is arranged afilter constituted for instance by a very fine steel sponge 30 whichstops the dust which might otherwise enter the apparatus. It alsocarries a knob 34 adapted to of the motor 2. This knob acts on a piston35 urged by the spring 36 into a position for which the circuit isbroken at 37. The stem carrying the knob 34 shows a bent part 38 adaptedto move (Figs. 1 and 4) inside a groove 39 provided at one end with oneor two notches 41 serving as stops for holding the bent part 38 in thecircuit-closing position. This relieves the operator from the strain ofholding the knob depressed.

. The working of the apparatus is as follows:

The operator who holds the tool through the handle 3, closes the circuitthrough the knob 34 which hecauses to slide along the groove 39 intoengagement with the notch 41. He is then at liberty to hold theapparatus with both hands through the handles 3 and 27. The shaft 5 isset rotating by the motor 2 and drives the cam 8 through the spring 12.The cam rotates and its slopes, moving over the rollers 9, compress andrelieve in alternation the spring 12. The cam reciprocates thuslongitudinally of the apparatus. In the example shown, there are twoforward strokes for each complete revolution of the shaft 5. Theprojecting parts of the cam hit at each forward stroke the tool carrier16 which is returned yieldingly after this stroke by the spring 23.

It is apparent that the dismantling of the apparatus is extremely easy:after unscrewing the spring, 23, I remove the tool proper. On the otherhand after removing the motor 2 from the casing 1, I may reach thegearwork 7. After separating the two parts of the casing l whichareinterconnected at 1' through lugs and bolts, I may reach all theinner parts. A mere unscrewing ofthespring 12 allows theshaft5 tobedisconnected with reference to the cam.

What I claim is:

1. An electrically controlled striking apparatus comprisingincombination: a handle, an electric motor to which this handle issecured, an electric circuit therefore, a two part casing enclosing achamber the longitudinal axis of which is parallel to the motor shaft, alongitudinal shaft in this casing chamber adapted to be driven by themotor, a cam adapted to rotate and move longitudinally on thislongitudinal shaft, rollers pivotally carried inside the casing andoperatively engaging the surface of the cam for moving it longitudinallyas it rotates;a helical spring connecting the cam with thelongitudinalshaft, a tool slidingly held in the casing, means controlled by the camfor imparting a longitudinal blow to the tool, on the casing a loweroutwardly threaded recessed part, two shoulders on the tool the first ofwhich penetrates in the lower recessed part of the casing, a two partwasher disposed between these shoulders and projecting beyond them, ahelical spring screwed over the lower threaded part of the casing, andthe coils of the free end of which are brought towards the axis of thespring in a plan perpendicular thereto, the size of said spring beingsuch that the washer bears on the last coils of the free end and thatduring the working, said spring brings back' the tool when thrustforward by the cam.

2. Anelectrically controlled striking apparatus comprising incombination: a handle, an electric motor to which this handle issecured, an electric circuit therefor, a two-part casing provided withan annular groove and enclosing a chamber the longitudinal axis of whichis parallel to the motor shaft, a handle, a collar carrying said handleadapted to rotatably fit in the groove of the casing, means for.securing the collar to the casing for different angular positionsthereof, a longitudinal shaft in this casing chamber adapted to' bedriven by the motor, a cam adapted to rotate and to move longitudinallyof this longitudinal shaft, rollers pivotally carried inside the casingand operatively engaging the surface of the cam for moving itlongitudinally as it rotates, a helical spring connecting the cam withthe longitudinal shaft, a tool slidingly held in the casing, meanscontrolled by the cam for imparting a longi- EMILE uton VIGNE.

